Sound box



H. J. DURBOROW.

SOUND BOX.

APPLICATION FILED DEC.16. 1920.

1,4269% Patented Aug. 22, 1922.

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Qpeciflcation of Letters Patent. P@ fij@mtd1 A 22 11% Application filedDecember 18,1920. serial Itc. 481,088.

To all whom it may concern:

Be it known that l, HARRY J. Dunsonow, a citizen of the United States,resldlng at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements in SoundBoxes, of which the following'ls a specification.

One object of my invention 1s to prov1de an improved sound box fortalking machines, which will be instrumental 1n more accuratelyreproducing sound than devices previously used for this purpose Anotherobject of my present inventlon 1s to distribute and equalize the impulsecaused by the connection of the stylus bar to the diaphragm prior to thepassage of the sound waves through the tone conducting portion of themachine.

A. further object is to make the devlce of my invention of a simple anddurable construction which can be readily manufactured.

These objects, and other advantageous ends which will be describedhereinafter, I attain in the following manner, reference being had tothe accompanying drawings in which Figure 1 is an enlarged fragmentarysec tion taken centrally through a sound box made in accordance with myinvention; the stylus bar being shown in outside view;

Figure 2 is a section taken on the hue 22 of Figure 1, v

Figure 3 is a front face view of a member whichforms a part of myinvention in the construction illustrated,

Figure 4 is an edge view of said member, and

Figure 5 is a rear view of said member.

Referring to the drawings, 6 represents the frame of a sound boxincluding a recess 7 in which is mounted a diaphragm 8;

said diaphragm being positioned between gaskets Q9 and 10; the gasketsbeing confined within the recess and between a ring 11 and a shoulder'12. A circular cavity 13 leads inwardly from theshoulder 12 andcommunicates with an axial passage 14 which forms a art of the soundconductis provided by a' nipple extension or sleeve 15 whereby the soundbox can be attached to a tone arm or other sound conducting member as iscommon practice in the manufacture of talking machines. .llhe stylus bar16 is centrally connected at 17 to the diaphragm 8.

A member 18, the detail construction of which is shown in Figures 3 to 5inclusive, fits within the cavity 13 and is held between the innersurface or wall 19 of said cavity 13 and the gasket 10. This member 13may be made of hard or tough springy wood and on its rear face has anumber of radially extending grooves 21. These grooves communicate witheach othen at the axis of the member 18 and lead outwardly to respectivenotches 22 which are cut into the. peripheral edge portion; said notchescommunicating with the space between the diaphragm 8 and the front face23 of the member 18. The portions of the face 20 between the grooves 21preferably engage the wall 19 and the gaskets 9 and 10 are preferably.made of rubber so as to resiliently hold the member 18} in place. Thusthere is a solid portion of the member 18 interposed between the centralconnection of the stylus bar with the diaphra and the sound outlet 14;the diaphragm 8 also being spaced from-the face surface 23 of the member18 to provide a chamber 24. The vibrations of the stylus bar 16 affectthe diaphragm 8, the greatest impulse occurring adjacent the. axis orcentral portion of the diaphragm, and sound waves are set up in thechamber 24; the stronger waves occurring in the central portion of saidspace. Ordinarily these( stronger sound waves would precede otherportions of the waves directly outward throughthe passage 14 ifthemember 18 were not present. With my improved structure, however, allof the sound waves are compelled to pass radially or to spread out fromthe axis of the chamber 2 1 and eventually pass through the notches- 22and grooves 21 and finally pass through the passage.

' I have found in actual experience that a more clear and definitereproduction is produced by the construction above described and alsothat the member 18 serves as a resonator which greatly improves thequality of the sound.

The member 18 therefore forms a resonat= ing partition which also servesin the ca-' pacity as a distributor and equalizer for the sound wavesset up by the vibration of the diaphragm.

- tion may be changed without departing from the spirit thereof, andhence ll do not limit myself to the preclse construction set forth, butconsider that I am at liberty to .make such changes and alterations asfairly come within the scope of the appended claims.

ving thus described my invention, what I claim as new and desire tosecure by Letters Patent is p 1. A resonating partition for use 1n atalking machinesound box case includmg a portion providing a soundoutlet passage, said partition being located between the diaphragm andthe sound outlet passage of one face and sound outlet openingscommunicating with said grooves, said grooves also being incommunicatlon with said sound outlet passage of the case; substantiallyas described. 1

2. A resonating partition for use 1n a talking machine sound box caseincluding 1 an inner wall having a sound outlet passage,

said partition being located between the rel-some die hragm andthe'inner wall of the case, sai partition, having passages leadingtoward the axis thereof and being in com- -munication with the soundoutlet paaage and with the; space between the partition and thediaphragm; substantially as described.

3. A resonating partition for use in a talking machine sound box caseincluding an inner wall having a sound outlet passage, said partitionbeing located between the diaphragm and the inner wall of the case, saidpartition having grooves in one face and notches communicating with saidrooves, said partition being. adapted to e placed in said case with saidface opposed to said wall of the case sothat said grooves providepassages communicating the case, said partition havlng grooves 1n withthe outlet passage and with said notches; substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses. J

HARRY J. nnanonow.

